SEOUL—Samsung Group announced annual management changes at its business units on Monday but said top executives at its flagship unit, Samsung Electronics Co., will remain in their current positions as the company seeks to reverse recent profit declines.

Samsung Electronics’ mobile business head, J.K. Shin, the chief of the company’s consumer electronics unit, B.K. Yoon, and the current chief executive for the component business, Kwon Oh-hyun, will all maintain their positions, Samsung said.